This invention concerns novel dicocoamine derivatives of 2,5-dimercapto-1,3,4-thiadiazole.
According to a particular embodiment, the invention relates to dicocoamine derivatives of 2,5-dimercapto-1,3,4-thiadiazole which possess improved corrosion resistance towards metals and lubricating compositions containing same.
Lubricants which are used for heavy duty service such as maintenance of diesel engines, internal combustion engines and the like contain a variety of additives to prevent their deterioration during use and to improve the overall performance of the lubricant. These additives can cause excessive wear of special components of the engine due to chemical reactions between the additive and the metal. Particularly detrimental are sulfur-containing additives which are widely used as extreme pressure agents and anti-oxidants. The sulfur compounds tend to corrode those metal parts which contain copper, bronze, silver and other sulfur-reactive metals.
In the past, corrosion of metals has been inhibited by adding to the lubricating composition 2,5-bis(hydrocarbyldithio)-1,3,4-thiadiazoles disclosed in U.S. Pat. No. 3,087,932 to Little and 2-hydrocarbyldithio-5-mercapto-1,3,4-thiadiazoles described in Canadian Patent No. 966,842 to Blaha.
It has now been discovered that improved corrosion protection of copper, bronze, silver and the like can be imparted to lubricating compositions by adding certain asymmetrical dicocoamine derivatives of 2,5-dimercapto-1,3,4-thiadiazole.